User's Manual

19-13
Cardiac Output Troubleshooting Guide
Clinical Situation Possible Cause Solution
Invalid pressure reading ■ Stopcock of the CVP or RAP line
may not have been turned OFF
quickly enough after injection was
made.
■ Turn the stopcock off immediately after
making the injection to provide the
module with the correct pressure value
at the time it obtains the curve.
Erroneous CO values
using room temperature
injectate
■ Injectate too warm. ■ Injectate temperature is above 25.5° C.
■ Injection rate too slow. ■ Administer bolus smoothly at a rate of
<
10 cc/4-seconds.
Unable to obtain indexed
values for calcs
■ Did not enter height and/or weight
prior to averaging curves.
■ Enter the height/weight and reinject the
curves.
■ If the Calcs option is installed, enter the
height/weight in hemocalcs to obtain
index values without reinjecting curves.
Value of calcs variable
displays as +++
■ Measured value is out of range. ■ Check computation constant (CC)
values for validity.
Spontaneous CO curves
drawn while in AUTO
mode
■ Infusion of IV drips or medications
through proximal port.
■ Turn off the IV solutions temporarily.
■ Mechanically ventilated patient
causing shifts in PA temperature.
■ Use the Manual mode.
■ Cardiac arrhythmias causing blood
flow variance.
■ Use the Manual mode and time the
injection during stable ECG rhythm.
Substantial variance in
CO values/irregular
curves
■ Varied temperature in bolus.
■ Injection delivered at varying points
in the respiratory cycle.
■ Standardize the temperature of bolus.
■ Use the Manual mode and time the
injection at end expiration, if desired.
■ Movement. ■ Standardize the patient position during
procedure.
■ Physiological problems. ■ Any of the following conditions can
affect accurate readings: ventricular
arrhythmias, low stroke volume, and/or
valve insufficiency.
■ Injectate rate too slow. ■ Administer the bolus smoothly at a
consistent rate.
No curve drawn after
bolus injected
■ Insufficient time has elapsed
between injections to allow blood
temperature stabilization.
■ Wait 60- to 90-seconds between
injections.